JDBC input plugin - no results from oracle db

[mato848]

Hi everyone,
I am trying to read some data from Oracle 11g database. My configuration is working, but only until some id.
For example following statement produces results into output

select * from sys_log where id > 10 and rownum < 10

But this statement not. Even when data are present in DB

select * from sys_log where id > 40900 and rownum < 10

It looks like db client fetches some data on start and doesn't give results for data outside this result set.
There are no error in the console. I am using logstash 5.5.0

here is my configuration

input { 
   stdin { }

    jdbc {
    jdbc_driver_library => "ojdbc7-12.1.0.2.jar"
    jdbc_driver_class => "Java::oracle.jdbc.OracleDriver"
    jdbc_connection_string => "jdbc:oracle:thin:@127.0.0.1:1523/DBSID"
    jdbc_user => "user"
    jdbc_password => "password"
    schedule => "* * * * *"
    statement => "select * from sys_log where id > 40900 and rownum < 10"
  }
 }
output {
  stdout { codec => rubydebug }
}

Can someone please help to determine if its a bug or if there is something wrong with my configuration ?
Thanks

[Mr.Flakes (Jurgis Babinskas)]

Since you stated that first statement produces results and second does not could it be a problem with the DB? Are you sure that data for the second statement is already commited and all other sessions can see that data?

[mato848]

Yes everything is commited. Actually i don't do any changes on the table.
Also i don't think there is something wrong wit the DB. I use it for other projects and everything works fine.